This invention is directed to voltage testers and, more particularly, to voltage testers for testing whether or not the voltage on a conductor falls outside of its normal range.
During telephone installation and testing, it is often necessary to determine whether or not the voltages on the tip and ring conductors are within their normal ranges. Normally the tip conductor voltage lies in the range of from 0 to -24 volts and the ring conductor voltage lies in the range of from -24 to -48 volts, these values being respectively 50 and 100 percent of nominal central office battery voltage. While these voltage ranges are relatively wide, if the voltages on the tip and ring conductors fall outside of these ranges, telephone circuitry connected to these conductors will operate incorrectly, or not at all.
It will be readily appreciated that due to the multiplicity of wires involved in a telephone system, occasionally wires are incorrectly connected such that the voltages applied to the tip and ring conductors are reversed. Or, unintentional open circuit or grounding of the tip or ring conductors may occur. Thus, it is desirable to provide a device that rapidly and quickly determines whether or not the voltages carried by the tip and ring conductors fall within their normal ranges. While a volt meter can be used to determine this information, such an approach is undesirable for various reasons. The major disadvantage is the time required to connect up, adjust and read a volt meter. A potential alternative approach is to use an illuminated indicator, in combination with a go--no-go test circuit. However, illuminated indicators require the inclusion of power supplies which require replacement or recharging. Thus, it is desirable to provide a tip and ring conductor voltage tester that can utilize preexisting circuit voltages as a source of power, particularly one that can be housed in the test equipment normally utilized by the telephone installer or maintenance man (such as his handset), and that will rapidly and automatically provide an indication of whether or not the tip and ring voltages are within their normal ranges.
Therefore, it is an object of this invention to provide a voltage tester suitable for testing the voltage on a conductor to determine if it lies within a normal range.
It is also an object of this invention to provide a tip and ring conductor voltage tester.
It is a further object of this invention to provide a tip and ring conductor voltage tester suitable for installation in the handset normally utilized by telephone installation and maintenance personnel.
It is a still further object of this invention to provide a circuit-energized tip and ring voltage tester that automatically tests whether or not the voltages on both the tip and ring conductors of a telephone line are within their normal ranges.